P. Birtwhistle, Great Shefford, Berks., England, writes that observationsusing a 0.40-m f/6.0 Schmidt-Cassegrain and identical exposures andmeasurement settings indicate an increase in coma size from 26" by 24" on Apr.17.1 UT to 38" by 34" on Apr. 18.1. K. Hornoch, from co-added R-band frameswith the 0.65-m telescope at Ondrejov on Apr. 18.0, noted a very stronglycondensed elliptical coma of 65" by 50", with the long axis in p.a. 55-235 deg.A. Novichonok and D. Chestnov, observing remotely at Cloudcroft, NM (0.18-mf/2.8 Newtonian reflector), on Apr. 19.3, described an extended 1'.0 by 0'.8coma of integrated magnitude V = 11.4. The improved orbit below, based on 356 observations extending to Apr. 19.6(mean residual 0".2), taken from MPEC 2010-H26, confirms the general featuresof that on CBET 2249, with the minimum distance from Jupiter in May 1976 nowrefined to 1.0 AU.

C. Drescher, Calamvale, Queensland, Australia, reports the discovery ofan apparent supernova (red mag 15.4) by Stuart Parker (Oxford, Canterbury,New Zealand), on an unfiltered CCD image taken by Parker on Apr. 19.755 UTwith a 35-cm Celestron C14 f/6.3 Schmidt-Cassegrain telescope (+ ST10camera). Drescher measures the position of 2010bv to be R.A. = 22h14m01s.89,Decl. = -26o55'44".6 (equinox 2000.0; using Astrometrica software with theUSNO-B1.0 catalogue), which is 15" west and 31" north of the nucleus of thegalaxy PGC 68345 (= ESO 533-4). The object is also visible on images takenby Parker on April 20.668, from which Drescher measured position end figures1s.91 and 44".4. Confirmation images taken by J. Brimacombe (Cairns,Queensland, Australia) taken on Apr. 20.779 with a 40-cm Ritchey-Chretientelescope (+ U16 camera) also show 2010bv (no position or magnitudeprovided). Nothing is visible at the position of 2010bv on a Digitized SkySurvey image from 1995 Aug. 29 (limiting red magnitude 20.5).

NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars.

Further to IAUC 9116, measurements by K. Battams and orbital solutionsby the undersigned for a SOHO comet detected by J. Ruan are given on MPEC2010-H37. This Marsden-group comet was at perihelion on Apr. 19.9 TT, 11.6days earlier than the prediction in the ICQ 2009/2010 Comet Handbook from theassumption (MPEC 2004-X73) that C/1999 J6 = C/2004 V9.

M. Knight, Lowell Observatory, presents plots of the photometry ofall three objects at http://www.lowell.edu/users/knight/research/1999j6.htmland from the similarity suggests that the three are almost certainly oneand the same object. The uncalibrated data show C/2010 H3 brighteningfrom mag 9.0-9.5 at discovery to mag 5.5 at the final C2 observation onApr. 19.56 UT, while in C3 the brightness was rather steady at mag 7 fromApr. 19.61 to Apr. 20.2, fading to mag 8-9 by Apr. 20.7. Knight adds thatthese three comets are brighter than any other observed Marsden-group members(see http://www.lowell.edu/users/knight/docs ... tation.pdf).

NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars.

E. Guido, T. Puckett, and J. Newton report the discovery of an apparentsupernova (mag 16.1) on unfiltered CCD images (limiting mag 18.5) taken witha 0.40-m reflector at Portal, AZ, U.S.A., on Apr. 25.26 UT in the course ofthe Puckett Observatory Supernova Search. The new object, which wasconfirmed at mag 16.0 on images (limiting mag 18.5) taken by T. Orff on Apr.26.16 with a 0.40-m reflector at Portal, is located at R.A. = 14h04m11s.29,Decl. = +33o18'22".2 (equinox 2000.0), which is 5".4 east and 6".2 south ofthe center of MCG +06-31-61. Nothing is visible at this position on imagestaken by Puckett on Apr. 12 (limiting mag 18.7).

NOTE: These 'Central Bureau Electronic Telegrams' are sometimes superseded by text appearing later in the printed IAU Circulars.

F. Colas, Observatoire de Paris, forwards a report by F.Manzini (Sozzago, Italy) of an 18th-magnitude condensed fragment inthe tail of this comet, along with a fainter fragment, on Mar. 13.0UT; follow-up images by Colas on Mar. 14.1 using the Pic du Midi1-m telescope confirmed a single 18th-mag object some 6" from themain nuclear condensation in p.a. 240 deg. N. J. Howes, Cherhill,Wiltshire, U.K., reported a fragment of mag about 18 located about3" in p.a. 240-253 deg from the primary component on Mar. 17 onimages taken through three filters with the Faulkes Telescope North;his images from Apr. 12 fail to show component 'B', suggesting itsdisintegration. E. Bryssinck, Kruibeke, Belgium, found a secondarycomponent 5".5 from the nuclear condensation in p.a. 258 deg ineight images (resolution 0".5/pixel) taken on Mar. 19.397 remotelywith a 0.4-m reflector at the Tzec Maun Observatory in New Mexico.Reports suggest that component 'B' was about 4 mag fainter thanprimary component 'A'. The astrometry of this new component 'B'from Mar. 17 to Apr. 9 has been included on MPECs 2010-F87,2010-G14, and 2010-G70.

F. Colas, Observatoire de Paris, forwards a report by F.Manzini (Sozzago, Italy) of an 18th-magnitude condensed fragment inthe tail of this comet, along with a fainter fragment, on Mar. 13.0UT; follow-up images by Colas on Mar. 14.1 using the Pic du Midi1-m telescope confirmed a single 18th-mag object some 6" from themain nuclear condensation in p.a. 240 deg. N. J. Howes, Cherhill,Wiltshire, U.K., reported a fragment of mag about 18 located about3" in p.a. 240-253 deg from the primary component on Mar. 17 onimages taken through three filters with the Faulkes Telescope North;his images from Apr. 12 fail to show component 'B', suggesting itsdisintegration. E. Bryssinck, Kruibeke, Belgium, found a secondarycomponent 5".5 from the nuclear condensation in p.a. 258 deg ineight images (resolution 0".5/pixel) taken on Mar. 19.397 remotelywith a 0.4-m reflector at the Tzec Maun Observatory in New Mexico.Reports suggest that component 'B' was about 4 mag fainter thanprimary component 'A'. The astrometry of this new component 'B'from Mar. 17 to Apr. 9 has been included on MPECs 2010-F87,2010-G14, and 2010-G70.

As first announced on CBETs 2249 and 2253, observations of anunusually bright asteroidal object (discovery observation tabulatedbelow), only 15 degrees from opposition, were reported by Jan Vales,observing with the 0.60-m f/3.3 Cichocki reflector at Crni Vrh,Slovenia; H. Mikuz writes that, while the discovery images show adistinct stellar profile, follow-up images with the same telescopeon Apr. 16.84 UT show that the object had become diffuse with aflatter profile than those of nearby stars of similar brightness.The numerous observations reported after posting on the MinorPlanet Center's 'NEOCP' webpage soon made it clear that the objectwas some 2.0-2.5 AU from the earth and therefore of absolutemagnitude 8-9. It was also soon clear that there were no recentobservations of the object in the MPC files, and R. A. Kowalski hasconfirmed that it was not present (down to V magnitude 20) inframes of the relevant region obtained by the Catalina Sky Surveyas recently as Apr. 15.4. Several observers in the day afterdiscovery indicated that the new object appeared slightly butconsistently larger than nearby field stars of similar brightness-- with a coma becoming noticeable and growing in size over thenext several days. E. Guido and G. Sostero compared the appearanceto that of comet 17P/Holmes in the early phases of its Oct. 2007outburst. Visual total-magnitude and coma-diameter estimates: Apr.16.45, 13.3, - (A. Hale, Cloudcroft, NM, U.S.A., 41-cm reflector;stellar appearance); 16.66, 12.9, - (K. Yoshimoto, Yamaguchi-ken,Japan, 25-cm reflector; stellar appearance; communicated by S.Nakano); 16.98, 12.7 (J. J. Gonzalez, Asturias, Spain, 0.20-mreflector; stellar appearance); 18.15, 11.7, 0'.5 (M. Goiato,Aracatuba, Brazil, 22-cm reflector); 19.08, 11.5, 0'.7 (Goiato);20.83, 12.7, 0'.4 (W. Hasubick, Buchloe, Germany, 44-cm reflector);22.02, 11.5, 1' (Goiato).